This website covers topics on knowledge management, personal effectiveness, theory of constraints, amongst other topics. Opinions expressed here are strictly those of the owner, Jack Vinson, and those of the commenters.

Some criticism of TOC

Stack of Dyed WoolIn case you think I am a dyed-in-the-wool Theory of Constraints promoter*, I point to this critique by Dan Trietsch from a 2005 issue of Project Management Journal: Why a Critical Path By Any Other Name Would Smell Less Sweet? Towards a Holistic Approach to Pert/Cpm.  Essentially, he says that Critical Chain Project Management is nothing new academically, and gives some small credit that the ideas work well.

Abstract: To maximize the potential of Critical Chain (CC) to enrich project management practice, I discuss Eliyahu Goldratt's work in the context of his entrepreneurial career. I show that PERT/CPM had been an instance of Goldratt's "Theory of Constraints" (TOC) before Goldratt had articulated it. I also highlight errors and questionable recommendations he made. Nonetheless, CC provides a more holistic approach than the typical practice before. I (1) discuss CC and TOC, including strengths and weaknesses, in the relevant context; (2) provide earlier sources for the major so- called Goldratt innovations; (3) identify opportunities for immediate improvement and future research highlighted by Goldratt's work.

While the title and publication suggest it is about the TOC project management solution (Critical Chain Project Management - CCPM), Trietsch covers much of the basics of Theory of Constraints in his criticism before getting to the main points about CCPM.

This article points to research from the 1960's by Wiest on "the critical sequence" that also showed up in discussion the Critical Chain mailing list in the past few months.  Based on the discussion, Wiest's idea is the same as the Critical Chain as described in the TOC community.  But I am fairly sure it doesn't touch on the other elements of making TOC work, which are the management changes that are needed for a business to successfully change their operating mode.  What are those things?  Avoiding multitasking; buffers; and abolishing focus on task-level due dates.  All of these have elements discussed in the academic literature. 

While much of what is embedded in the CCPM world has been known academically, the simple problem is that most people do not practice project management according to these ideas.  Even at the larger scale of "constraints management" as discussed in the Operations Research community, I believe many of the principles are well understood but not applied in the business world.  This is the greatest frustration of all, no matter what you call it. 

The value I find in the Theory of Constraints community is that there are practitioners who are trying to apply these ideas both in their own businesses as well as with their customers.  That said, it's interesting to learn more of the academic underpinnings and to listen to the larger community of people who work in this area.  There are always things to learn in working with human beings.

From the tone of the article, it sounds as if Trietsch has had a long-standing complaint about Goldratt and TOC.  I've heard this in general in the TOC community: that the focus is much more on figuring out how to make the concepts work in practice than it is on rigorous proofs and thorough literature reviews.

* I am mostly a dyed-in-the-wool TOC promoter.

[Photo: "Stack of Dyed Wool" by Alistair Dunning.]

Another look at categorizing KM: PKM

Behaviors are contagious